Page 609 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

Implementation and Communication Best Practices Best Practice 1 2.2

Process condition change Select experienced rotating equipment personnel
Piping and foundation change Ideally, design and field experience are the best combination
‘Unit’ (driven, driver, transmission, auxiliaries) Provide site specific training
Ambient conditions Measure results
Provide opportunities for networking with other specialists
within and outside the company:
Fig 12.1.16 The rotating equipment environment User groups
Industry conferences
Regional conferences
Include analysts in all phases of new projects
Think system!
Every component is a part of a system
In order to determine root causes, systems and not just Fig 12.1.18 Analyst development strategy
components must be considered

evolved from industries where ‘production components’ are
Fig 12.1.17 The concept of a system
used, i.e. the electronics and automotive industries. However,
the rotating equipment unit, regardless of type, always becomes
Figure 12.1.18 suggests ways to build and develop a practical, customized by virtue of its environment. That is, each rotating
strong analyst group. equipment unit has its own signature. Consequently, care must
Utilize practical, correlated assessment techniques whenever be exercised when applying statistical methods to rotating
possible. equipment reliability assessment. Figure 12.1.19 presents this
Today, many statistical methods are available to the analyst to important fact.
determine causes of failure and to predict equipment and
component life. The personal computer makes the use of these
methods quick and easy.
Since every rotating equipment unit, regardless of size, represents
However, the reader is cautioned to regard all statistical a ‘customized system’, care must be exercised when assessing the
methods as only a part of the process. Whenever possible, actual results obtained by statistical methods.
data concerning failure rates should be used and the correlation
of statistical methods should be defined. It should always be
remembered that the basis for most statistical methods have Fig 12.1.19 Statistical methods and rotating equipment

Best Practice 12.2Practice 12.2
Best
Use site PDM results (predictive maintenance program) to resulted in revenue losses of over $1 MM. The adopted ‘continuous
continuously improve machinery best practices to maintain improvement best practice’ was to install an additional
a site machinery reliability program of the highest level. accumulator at the next turnaround and continue the quarterly
Continuous improvement means increasing the effectiveness of the accumulator checks (one at a time). See B.P. 7.14.
established site best practices by monitored results. b. A worn steam seal in a large steam turbine/compressor train
An effective site PDM program using the principles of component allowed steam condensate to enter the oil system requiring an oil
condition monitoring as defined in this book (See B.P. 10.11 and 11.7) conditioner to be installed and several on line oil changes to
will identify improvements that can be made to further increase site prevent a shutdown of the unit. This unit was supplied with a gland
machinery safety and reliability. condenser vacuum gauge that was continuously monitored and
UseB.P. 12.1 to justify continuous improvement recommendations to indicated vacuum eductor wear. This issue was not corrected since
management and obtain management approval for their implementation. the single eductor could not be shut down for corrective measures
(orifice replacement). The adopted ‘continuous improvement best
Lessons Learned practice’ was to install an additional gland condenser vacuum
eductor at the next turnaround. See B.P. 5.9.
Failure to continuously improve site machinery reliability
best practices will result in reduced reliability.
The following two examples show the results of not increasing the Benchmarks
effectiveness of established site best practices: This best practice has been used since the mid 1990s as ‘continuous
a. One accumulator was installed in a critical compressor train (un- improvement recommendations’ to increase the effectiveness of site
spared) lube oil system to prevent a low oil pressure trip. The unit best practices. These recommendations are included in all site audit
tripped on low oil pressure while the accumulator was being and site specific training workshop reports. Clients have always ac-
checked for pre-charge and bladder condition on a quarterly basis. knowledged that these ‘continuous improvement recommendations’
After this incident, the quarterly checks of the accumulator were have significantly increased site machinery safety and reliability.
canceled only to cause an additional shutdown. Each shutdown

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